import java.util.*;

public class code {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        //1.读入数据
        int n = in.nextInt();
        int q = in.nextInt();

        int[] arr = new int[n+1];
        for (int i = 1; i <=n ; i++) {
            arr[i] = in.nextInt();
        }

        //2.预处理一个前缀和数组
        long[] dp = new long[n+1];
        for (int i = 1; i <= n; i++) {
            dp[i] = dp[i-1] + arr[i];
        }

        //3.使用前缀和数组
        while(q>0) {
            int l = in.nextInt(),r = in.nextInt();
            System.out.println(dp[r]-dp[l-1]);
            q--;
        }

    }
}
